President Barack Obama admitted on Monday that America has "more nuclear
weapons than we need" and pledged to seek another far-reaching
disarmament agreement with Russia.

A Strategic Arms Reduction Treaty signed in 2010 binds Russia and the US to cut their arsenals to a maximum of 1,550 deployed nuclear warheads each by 2018.

But speaking in South Korea after a summit on nuclear security, Mr Obama said that more cuts could be made.

"My administration's nuclear posture recognises that the massive nuclear arsenal we inherited from the Cold War is poorly suited to today's threats, including nuclear terrorism," he said.

The administration was now conducting a "comprehensive study of our nuclear forces," added Mr Obama, saying: "Even as we have more work to do, we can already say with confidence that we have more nuclear weapons than we need."

America currently has about 1,950 deployed nuclear warheads, compared with 2,430 for Russia. However, the Russian stockpile is deteriorating rapidly, with the number of operational warheads falling every year.

As such, Russia could probably meet the limits in the existing treaty simply by allowing its arsenal to decay at its present rate. The US, by contrast, will have to make actual cuts to meet the agreed limits.

"I firmly believe that we can ensure the security of the United States and our allies, maintain a strong deterrent against any threat, and still pursue further reductions in our nuclear arsenal," said Mr Obama. "We'll continue to seek discussions with Russia on a step we have never taken before: reducing not only our strategic nuclear warheads, but also tactical weapons and warheads in reserve."